Binding wire clip



Nov. 7, 1950 J. K. NEwELL, .JR

BINDING WIRE CLIP Filed Aug. s1, 1949 Inventor: James K. Newell Jr:

His Attorney.

Patented Nov. 7, 1950 BINDING Wlan CLIP James K. Newell, J r.,Swampscott, Mass., assigner to General Electric Company, a. corporationof New York Application August 31, 1949, Serial No. 113,345

2 Claims. (Cl. 171-252) My invention relates to binding devices and moreparticularly to a binding wire -clip for use in securing binding bandson the rotors of dynamoelectric machines.

1n the manufacture of the rotor members of dynamo-electric machines ofthe direct current type it is common practice in order to secure thewindings of such rotors in place to provide binding bands at the endsthereof. To form such bands binding wire which resembles piano wire inappearance is tightly wrapped in a plurality of turns about the rotorand the ends of the wire and then secured tightly with respect to theband to prevent unwinding of the wire during operation of the machine.

Various methods and devices have been employed to fasten the ends of thewire used in binding bands. Such methods and devices include solderingand brazing and various forms of holding devices such as clips and thelike. In general however, existing methods tend to have certain.disadvantages such as excessive cost `or tendency to loosen at therelatively high temperatures encountered in certain applications.Furthermore in the use of certain holding devices 'skewing of the turnsof wire forming a binding band may result due to the existence of aforce couple caused by the tendency of the ends of the binding wire topull and unwind in opposite directions. Itis, of course, obvious thatthe failure of a binding band may cause serious damage by entanglementof the loosened wire in other portions of the inachine and by permittingthrow-out of the rotor windings.

It is an object of my invention to provide a 1 new and improved bindingwire clip for use in securing the ends of binding wire in the forming ofbinding bands on the rotors of dynamoelectric machines.

It is another object of my invention to provide a clip of the typementioned which is inexpensive to manufacture and which has a highdegrec of reliability in securing the ends of binding wire in theforming of binding bands.

It is a further object of my invention to provide a clip which isprevented from skewing due to the force couple imposed on such a clip bypulling of the ends of binding wire.

According to one embodiment, my invention provides a clip formed of athin strip of a bendable material, such as metal, arranged to beinterwoven with the turns of wire of a binding band and to link the endturns thereof, and to have the ends of the strip welded or otherwisefastened together to form a closed member. By

interweaving the clip with the turns of wire an interlockingconstruction is formed which is highly resistant to action of a forcecouple, thereby permitting the ends of the binding wire to be securedtightly to the clip and at the same t`.ne preventing skewing of theturns and clip.

My invention will be better understood from a consideration of thefollowing description taken in connection with the figures of theaccompanydrawing' and the appended claims, in which features of myinvention believed to be novel more particularly set forth.

la is an elevational view of a clip constructed in accordance with myinvention and assembled with a binding band; Figs. 2 and 3 are sectionalVViews showing certain features of the arrangement or" Fig. l; Fig. 4 isa plan view of another type of clip showing the effect of skewingaction; and Fig. 5 is a sectional view of the arrangement of Fig. 4.

Referring to Fig. 1 there is shown in assembled relation a portion of abinding band I for a rotor (not shown) of a dynamoelectric machine andbinding wire clip 2 including certain features of my invention. Bindingband I comprises a plurality of turns 3 of binding wire 4, preferably ofa type having a relatively high degree of tensile strength yet beingbendable. Wire 4 is wound tightly about a rotor to form clampingengagement with the windings thereof, thereby tending to secure thewindings in place on the rotor. Fig. la is an elevational view of theportion of a band shown in Fig. i indicating the curvature thereof.Binding wire 4, as employed to form turns 3. is preferably a continuousp-iece of wire. The end turns 5 and of band I which form the extremitiesthereof, include therefore the opposite ends 'l and S of binding wire 4.It is the principal function of binding wire clip 2 to secure ends 'iand 8 of binding wire l! tightly with respect to band I to preventloosening of band I by unwinding of binding wire Il.

Attention is next directed to Figs. 2 and 3. Fig. 3 is a sectional viewof binding band I and binding clip 2 taken along line 3-3 of Fig. l.Fig. '2 is generally similar to Fig. 3 with the exception that clip 2 isshown prior to a final bending operation thereon. Referring first toFig. 2, the details of construction and assembly of clip 2 with respectto binding band I are shown therein. Clip 2 is formed of a strip 9 of abendable material, preferably metal. The center .portion of strip 9 ispositioned underneath band I so as to lieV between band I and the rotorwindings being l .y 3 clamped thereby. The end portions of strip 9 arebent up around end turns and 6 of band I.

In accordance with my invention I interweave a portion of strip 9between turns 3 by passing strip 9 under a portion thereof to achieve aninterlocking engagement between turns 3 and strip 9. The portion ofstrip 9 interwoven with turns 3 is indicated in Fig. 2 by numeral Id.The end portions or extremities of strip 9 designated by numerals il andI2, are brought to a common point at which they are suitably joined. Inorder to bring end i E of strip ii to a common point with end I2, strip9 is again brought to the outer surface of band l leaving underlyingportion I@ of strip 9 in its interlocked position relative to turns 3.Ends II and I2 of strip 9 may then be joined to form strip 9 into acontinuous or closed member. l/Vhile a number of methods of joining endsII and I2 may be employed, I have iound that spot-welding is aneconomical and convenient means of joining ends Ii and i2. Such a weldis shown in Fig. 2 and is designated by numeral I3.

The nal operation in the installation of clip 2 consists of bending theportion of clip 2, designated by numeral I4, which is formed by joiningends II and I2 of strip il, against the outer surface of band I to makeportion I4 generally parallel therewith. The direction of such bendingis indicated by a broken line I5 in Fig. 2. The final position ofportion le after bending is shown in Fig. 3 and also in Figs. 1 and la.It will be noted that a pair of welds I3 is shown in Fig. 1. It will beunderstood that the number of welds employed is dependent on the lengthof clip 2 along the periphery of band I. In general I have found that apair of such welds is suicient to join the ends of a normal clip,although in the case of a relatively narrow clip a single weld may besufcient.

The structure and assembly operations of clip 2 as thus far shown anddescribed are for the purpose of securing clip 2 in an interlockingengagement with respect to band I. The final operation for the purposeof securing ends l' and 3 of wire l to clip 2 consists of bending ends'l and 8 sharply against the edges of clip 2 prior to cutting ends l and8 to a convenient length. Such sharp bends are highly effective insecuring ends 'i and 8 to clip 2, since a relatively high degree ofbending effort is required to unform such sharp bends. It is of courseessential that the material chosen for Wire li be able to withstandvrelatively sharp bending without danger of failure.

One of the principal advantages of my invention as embodied in theconstruction shown and described, is the prevention of skewing ofbinding clip 2 due to the force couple resulting from pulls in oppositedirections by ends l and S indicated by arrows I6 and Il respectively inFig. 1. Such a skewing action is illustrated in Figs. 4 and 5, wherein aclip 2 similar in certain respects to clip 2 of Fig. 1 is assembled on abinding band l similar to binding band l of Fig. l. The elements shownin Figs. 4 and 5 are designated by prime numerals similar to thenumerals employed for similar elements in Figs. l and 3. In Fig. 5 thereis shown a sectional view of clip 2 and band I taken alongline 5-5 ofFig. 4. It will be seen that clip 2 is generally similar to clip 2 asshown in Figs. 2 and 3 except that strip 9 from which clip 2 is formedis arranged to link all the turns 3 of band I' and that strip 9accordingly is not interwoven with turns 3 to form an interlockingengagement between band I and clip 2. In Fig. 4 the effect is shown Vofa couple produced by the forces of ends l and 3' pulling in oppositedirections as represented by arrows It' and Il respectively, tending toproduce a twisting or skewing effect in clip 2 with an accompanyingtendency to displace turns 3 from their normal positions.

In accordance with my invention I reduce such skewing effects to aminimum by providing restraining forces by interlocking clip 2 withbinding band I. More particularly, in the arrangement shown in Fig. 3 arestraining force is established at the point where strip 9 istransferred from the outer surface of band i to the undersurfacethereof. The general point of the application of such force is indicatedby numeral I8. Again, when strip 9 is returned from the undersurface ofband I to the outer surface thereof a second restraining force isapplied at a point indicated generally by numeral I9. The force appliedat point Ii) is particularly effective because of the sharp bend placedin strip 9 when joint portion ill is bent against band I, causing tightcontact between strip 9 and the particular turn 3 around which strip 9is bent.

The width of strip 9, which determines the length of clip 2 along thecircumference of band I, is preferably made relatively great withrespect to the width of band I to provide a maximum amount of force fromthe interlocking of clip 2 and band to oppose the force couple tendingto produce a skewing effect. While mention has been made of restrainingforce produced by the interlocking action described, and the presence ofsuch forces has been indicated particularly at points I8 and i9 in Fig.3, it will be obvious that inherent restraining forces are obtained byrelatively tight contact between strip 9 and end turns 5 and E of bandI. However, I have found that for a high degree of reliability insecuring ends l and 8 and in preventing a skewing action, it is highlydesirable to supplement such inherent forces by providing additionalrestraining forces through an interlocking engagement between clip 2 andband I as illustrated by the forces at points I8 and i@ in Fig. 3.

While I have shown a particular interweaving arrangement between stripEl and turns 3 it will be obvious that my invention is not limited tothe particular arrangement shown but includes other interweavingarrangements. The number of end turns of a binding band to be includedin the linked portions at the extremities thereof and the number oftimes the strip forming a binding clip is interwoven from the outersurface to the undersurface of the band is dependent on the requirementsof particular applications encountered. I have found that thearrangement herein employed is particularly suitable for a large numberof applications from the standpoint of effectiveness, reliability andease of construction.

While I have shown spot-welding as a preferred means of joining ends liand I2 of strip 9 other means may readily be employed. In addition tospot-welding other fusible joining means such as brazing or solderingmay be employed in various applications, depending on operatingtemperatures to be encountered, or the clip ends may be joined bymechanical means such as folding or riveting.

It has been found in the construction of rotors for dynamoelectricmachines that if both ends of a binding wire employed to form a bindingband may be securely held relative to the band, it is unnecessary tosolder or otherwise fasten together the entire group of Wires forming'the band. By the use of a binding clip embodying the features ofinvention to secure the ends of a binding wire in the manner described,I have found that the troubles encountered due to failures of bindingbands may b e reduced to a minimum by elimination of skewing andsubsequent loosening of the turns of binding wire forming the band.Furthermore the use of such a binding band and clip provides a bindingarrangement which is simple in construction and inexpensive tomanufacture since only simple tools and common materials are required.

While I have shown and described a preferred embodiment of my invention,it will be understood that my invention may well take other forms and I,therefore, aim in the appended claims to cover all such changes andmodifications as fall within the true spirit and scope of my invention.

What 1 claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. In a dynamoelectric machine the combinan of a binding band for therotor of said mane, said band comprising a plurality of closely- :edtightly-wound turns of binding wire ar- -d to be maintained in clampingengagement the windings of said rotor, and a binding clip to secure theends of said wire relative to said band, said clip being formed of astrip of a bendmaterial, said strip being interwoven with turns in adirection normal thereto to form interlocking engagement therewith andarranged to link the end turns forming the extremities of said band andincluding the ends of said wire, the extremities of said strip beingfastened together to form a closed member, and the ends of said Wirebeing bent against said clip to form interlocking engagement therewith.

2. In a dynamoelectric machine the combination of a binding band for therotor of said machine, said band comprising a plurality of closelyspacedtightly-Wound turns of binding wire arranged to be maintained inclamping engagement with the windings of said rotor, and a binding clipto secure the ends of said wire relative to said band, said clip beingformed of a strip of a bendable material, said strip being interwovenwith said turns in a direction normal thereto to form interlockingengagement therewith and arranged to link the end turns forming theextremities of said band and including the ends of said Wire, theextremities of said strip being fusibly joined together to form a closedmember, the portion of said member including said joined extremitiesbeing folded against the periphery of said band so as to be generallyparallel with said periphery, and the ends of said wire being bentagainst said clip to form interlocking engagement therewith.

JAMES K. NEWELL, JR.

REFERENCES CITED The following references are of record in the .le ofthis patent:

UNITED STATES PATENTS Number Name Date Re. 11,735 Marshall Apr. 18, 18991,190,456 Pridgen July 11, 1916 1,823,607 Jungk Sept. 15, 1981

